The atlas found that Beverly Hills has 2,481 — the highest per capita in the region. Long Beach boasts 2,859 pools, Rancho Palos Verdes 2,592. It could not come up with a total for the city of Los Angeles, because the count left out the San Fernando Valley. The Brentwood section of the city, though, has 1,920.

But two other Los Angeles neighborhoods have no backyard pools at all: Watts and Florence. Of the four public pools in area parks, three apparently were closed for the season and empty when the satellite photo was taken, said Catarah Hampshire, a spokeswoman with the Los Angeles County Department of Parks and Recreation.